Device for controlling the transmission of power to pumps



May 28, 1940. J. c. MYERS I 2,202,504

DEViCE FOR CONTROLLING THE TRANSMISSION OF POWER TO PUMPS Filed April26, 1959 2 Sheets-Sheet 1 Ma 28, 1940. N J. c. MYERS 2,202,504

DEVICE FOR CONTROLLING THE TRANSMISSION OF POWER TO PUMPS Fiied April26, 1939 2 Sheets-Sheet 2 .5 To PPM/6 .Srw-rc atented May 28, 1940DEVICE FOR CONTROG THE mssroN or ran an r John C. Myers, Sperry, Okla,assignor of onehalf to .l. W. Scott Drilling Company, Okla, acorporation of Texas Application April 26, 1939, Serial No. 270,096 I 18Claims.

This invention relates to devices for controlling the transmission ofpower to pumps, and more particularly to the operation of pumps forlifting liquids,.the object beingto provide an emcient 5 means forautomatically stopping such pumps in response to the delivery of air, orother gaseous fluid to the pumps.

The capacity of many pumps is greater than that of more or lessuncertain sources of liquid delivered to the pumps, and it is usuallyadvisable to stop the pumps when the delivery of liquid is discontinued.For example, water or oil may be profitably pumped at intervals frommany wells without exhausting the supply of liquid, but the intervalsare usually uncertain, and the delivery of air or other gas to the pumpsis likely to result in abrasion at the pump itself, and destructivestresses in the operating mechanism. By automatically stopping suchpumps when the 80 delivery of liquid is discontinued, the presentinvention positively elminates the above mentioned hazard, and providesfor, safe and economical pumping of the liquid.

In the use of pumps for lifting oil from wells,

95 a single operator is often required to attend to the pumping of manywidely scattered wells. The operator usually begins by going from onewell to another to start the pumps, or to inspect the pumping mechanism,and he then attends td other duties. Experience has very clearly shownthat when the flow of oil to such pumps is discontinued, the pumpsshould be immediately stopped, but in actual practice the operator isunable to constantly observe the conditions at all 85 of the wells,especially where thewells are widely separated and a number of pumps areoperating at the same time. A'similar condition arises when a person hasonly one well to contend with,

as a single pump does not usually justify constant 40 attention, and maybe inspected only once or twice a day, perhaps to start the pump in themorning and stop itgin the evening.

However,- the operation of a pump after the flow of oil is discontinuedresults in several 45 serious disadvantages, due to the delivery of air,

or other gaseous fluid, to.the' pump.- This co'n- .dition produces achurning action which emu1- sifies the oil remaining in the well, andcauses undue wear on the working parts of the pump, at the same timesubjecting the pumping mechanism to destructive jerking which causesfatigue in the metal and is likely to break the sucker rods, thereby"requiring to remove the broken rods.

B6 The emulsifiedoil is stay troublesomeprcduct not acceptable to pipeline companies'and excessive friction in the working barrel of the pumprequires the operators to pull the long tubing, sucker rods and pumpfrom the deep well, in order that the worn parts may be replaced. All ofthis involves a loss of production of oil during the' period requiredfor repairs, as well as increased operating costs, and the production ofthe objectionable emulsified oil for some time after the repairedpumping mechanism is restored 10 and placed in service.

Another important advantage of the invention appears in. the fact thatit permits the ordinary simple pumping equipment to be safely used inpumping oil fromyery deep wells. Heretofore, such simple equipmentcomprising a reciprocable plunger near the bottom of the well, andsucker rods connecting the plunger to operating means above the ground,has been regarded as unsafe for pumping oil from very deep wells whereincontinuous pumping would temporarily exhaust the wells. The destructivestrains and abrasion due to delivery of air or gas to the plunger arelikely to break the extremely long sucker rods, or cause other injurythat would be impossible, or not feasible, to repairin a very deep well.The new device automatically stops the pumping mechanism in response tothe delivery of air or gas to the pump plunger, thereby providing forsafe and economical pumping of oil or other liquid from deep wells.

With the foregoing and other objects in view, the invention comprisesthe novel construction, combination and arrangement of parts herein- Iafter more specifically described and shown in the accompanyingdrawings, which illustrate one form of the invention. However, it is tobe understood that the invention comprehends changes, variations andmodifications within the scope of the claims hereunto appended. 4

Fig. lis-a diagrammaticalview of apumping apparatus embodying featuresof this invention.-

Fig. 2 is a vertical section on a largerscale, with parts broken away,showing the pumpplunger which operates in a cylindrical working .45barrel near the bottom of the well.

Fig. 3 is a section illustrating a stopping device adapted todiscontinue the transmission of power to the plunger when air or othergaseous fluid is admitted tothe plunger.

Fig. 4 is an enlarged section on the line- 51-43 in Fig. 3 showing alatch member separated from a driven member.

Fi 5 isa viewlsimilar to Fig. 4, showing the} latcnmember engaged withthe driven member 55 to prevent continued downward movement of the pumpplunger.

Fig. 6 is a diagrammatical view illustrating another form of theinvention.

Fig, 7 is a detail view of the automatic stopping device shown in Fig.6.

To understand the principle of the invention, one should bear in mindcertain conditions existing in an ordinary pump. Therefore, without inany way limiting the claims, I will briefly describe a few details of anoil well pump, and then refer to special conditions employed by me tocontrol the automatic stopping device.

Anordinary simple pump of this kind, shown in Fig. 1 and Fig. 2,comprises a cylindrical working barrel l located near the bottom of thewell, and a string of tubing it through which the oil is lifted fromsaid working barrel to a discharge pipe !2 above the surface of theground. A pump plunger l3 reciprocating in the working barrel I0 isusually operated by a string of sucker rods l4 extending upwardly fromthe plunger and connected to the operating mechanism above the ground.The bottom of the working barrel Ill may be equipped with a simple checkvalve l5 to provide for the admission of oil to the working barrel.plunger l3 may be equipped with a traveling check valve l6 which opensduring each down- Ward stroke, as the plunger falls in the workingbarrel, and closes in response to each upward stroke when the plunger islifted to discharge the oil. These movements of the plunger and checkvalves draw the oil from the surrounding casing I'l into the 'workingbarrel l0 and thereafter lift the oil through the tubing .II whichextends upwardly from the working barrel.

Attention is now directed to the following conditions:

The weight to be lifted consists of the long string of sucker rods Hi,the plunger l3, and the weight of the long column of liquid extendingfrom the check valve N3 in the plunger to the discharge pipe l2 abovethe ground. However, during each normal downward stroke, the check valve[5 at the bottom of the working barrel is closed, and there is a columnof oil extending from this bottom check valve to the upper end of thetubing ll. As a consequence, during each normal downward stroke, thesucker rods and plunger merely fall in this'column of liquid, and theweight is then limited to the actual weight of the sucker rods andplunger, minus the buoyant effect of the body of liquid, so that thefalling weight during the normal downward stroke is even less than theactual weight of the sucker rods and plunger.

When air or gas is drawn into the bottom of the working barrel It), theweight to be lifted during an upward stroke would again consist of thesucker rods and plunger, plus the weight of the tall column of oilsupported on the plunger. However, if we assume that air or gas is drawninto the working barrel, and that there is no oil between the checkvalve IS in the plunger and the check valve l5 at the bottom of theworking barrel, the weight during a downward stroke would beapproximately the same as the weight to be lifted during anupwardstroke. In this event the check valve IS in the plunger willremain closed, due to the downward pressure of the tall column of oil.Instead of merely falling in a buoyant liquid, the plunger is now forceddownwardly by this very heavygcolumn of liquid, and the air below theplunger will be readily com- The reciprocating.

pressed by this high pressure, or forced backwardly through any leak atthe bottom check valve l5.

I will hereinafter explain how I can take advantage ofthis abnormalweight to permit excessive downward movement of the plunger when a bodyof air or gas enters the pumping apparatus. Briefly stated, thisexcessive downward movement may be utilized to actuate the automatiostopping device, thereby stopping the transmission of power to the pump.In the preferred form of the invention, the stopping device includes aspring which permits said excess downward movement of the plunger inresponse to the presence of gaseous fluid below the plunger, and astopping member operated by the transmission of movement from saidplunger during said excess downward movement.

The operating meansshown in Fig. 1 comprises a pump jack l8 having apivotal support l9 and connected by means of a cable 20 to a polish rod2| at the upper end of the string of sucker rods IE. The means foroperating said pump jack comprises a pull line 22 connected to the jack,and an eccentric 23 driven by a rotary power shaft 24, said eccentricbeing surrounded by a band 25 connected to a pull rod 26.

To illustrate a suitable means for transmitting power from the pull rod26, I have shown a hook 21 at one end of said pull rod, and a link 28pivoted at 29. The hook is normally coupled to the link 28 as shown byfull lines in Fig. 1 and Fig. 3, but under certain conditions, the hookwill move to the left independently of the link, thereby permitting saidlink to drop by gravity to the position shown by dotted lines. In otherwords, the link 28 is an uncoupling member adapted to release the pumpplunger from the source of power.

To illustrate a means for stopping the pump plunger, I have shownnotches 30 f0rming abutments in the driven rod 22 (Fig. 3) and a latchmember 3| adapted to enter either of said notches. Assuming that thelatch member is located in one of said notches so as to stop the pumpplunger, the hook 21 may'then move to the left with the result ofreleasing the uncoupling link 28 and discontinuing the transmission ofpower to the stepped plunger.

However, the link 28 "is normally coupled to the hook 21, and the latchmember 3| is normally located in the elevated position shown "in Figures3 and 4 wherein its lower edge is spaced from the notched rod 22. Themeans for retain- .mg said latch member 3| in its elevated positioncomprises a slidable pin 32 adapted to lie within the enlarged lowerportion of a slot 33 in the latch member, as shown in Figures 3 and 4,and a light spring 34 tending to retain saidpin in this position. Anoperating handle 35 may be connected to the latch member 3| .for thepurpose of lifting said latch member to the position shown in Fig. 3. Iwill hereinafter describe a means for moving the pin 32 to the left inFig. 3, so as to locate the reduced portion 36 of said pin at the slot33, thereby releasing the latch and permitting it to fall onto thenotched rod 22. Continued movement of said rod 22 will permit the latch3| to enter one of the notches 30, so as to stop the rod 22, and releasethe uncoupling link 28. I

It is to be understood that when the pin 32 is moved to the left in Fig.3, the latch 3| will immediately fall onto the notched rod 22 andthereby locate the reduced portion 36 of the it against one side of thelatch, but the friction due to .such spring pressure will be overcome bythe weight of the latch 3| and its operating handle 35, so this frictionwill not prevent the latch from dropping into one of the notches 30.

I have shown two of the notches 30, so that if the latch fails to enterone of the notches it will have an opportunity to enter the secondnotch.

Attention is now directed to the devices shown in Fig. 3 fortransmitting power from the link 23 to the rod 22. A driving device maybe formed by a cap 31 screwed into a spring housing 38, said link 23being connected to said cap, and the spring housing being provided withan abutment. 39 engaged by a power-transmission spring 40. The notchedrod 22 has a reduced end portion 4| extending through the spring 40 andprovided with a spring seat 42 adjustably secured by a nut 43 screwedonto said reduced portion 4|. The spring 40 is located directly between.the spring seat 42 and the abutment 39 at the inner end of the springhousing, so the seat 42 can be adjusted to vary the.initial compressionof the spring. A guide cage 44 is adjustably screwed onto the rod 22 andslidably mounted in an outer housing 45, said guide cage having anabutment 46 at its inner end adapted to engage and operate the pin 32.However, under normal operating conditions, the stroke of said abutment46 is not longenough to reach the pin '32, the extreme normal movementto the left being suggested by dotted lines in Fig. 3. As a factor ofsafety, the outer housing 45 is pro- ;vided with a bumper plate 41adapted to be engaged by the abutment 46.

To understand the operation of the automatic stopping device shown inFigures 1 to 5, inclusive,

it is necessary to carefully consider a number of different-conditions.The spring housing 33 and its cap 31 are to be regarded as drivingmembers,

while the notched rod 22 and the abutment 46 near one end of said rodare regarded as driven members, the driving power being transmittedthrough the spring 40. Also bear in mind that during each lifting strokeof the pump plunger there is a severe load consisting of the weight ofthe sucker rods and pump plunger, plus the weight of the very tallcolumn of liquid to be lifted.. This load is great enough to compressthe power transmission spring 40 in response to each lifting stroke ofthe pump plunger, said spring being retained under compressionthroughout each lifting stroke.

However, during each downward stroke of the pump plunger, the travelingcheck valve 1 6 in the plunger is open while the check valve I at thebottom of the working barrel I0 is closed, and there is a column of oilextending from this bottom check valve to the surface of the ground. Asa consequence, during each normal downward stroke, the sucker rods andplunger merely fall in this body of liquid, and the weight is thenlimited to the actual weight of the sucker rods and plunger, minus thebuoyant effect of the body of liquid, so the falling weight during thenormal downward stroke is even less than the actual weight of the suckerrods and plunger,

The compression of the spring 40 is, therefore, relieved during eachnormal downward stroke of the plunger. Of course, the falling weight maybe great enough to slightly compress the spring, but in any .event, thecompression is considerably less than the compression which occurs tallcolumn of liquid, .this falling weight pulls the notched rod 22 to theleft in Fig. 3, and when the plunger reaches the end of its normaldownward stroke, the abutment 46 carried by said rod 22 may be locatedin the position shown by dotted lines in Fig. 3,: adjacent to butseparated from the pin 32. Under these normal operating conditions, saidabutment 46 does not move far enough to release the latch 3|.

Assuming now that the delivery of liquid to the pump plunger isdiscontinued, and that air or other gas is drawn into the lower portionof the working barrel beneath the plunger. During an upward stroke, ,thespring 46 will be compressed as usual, due to the weight of the plungerand sucker rods, plus the weight of the tall imately the same as theweight to be lifted during an upward. stroke. Therefore, the spring 40will be retained under compression, and as a consequence, the abutment46 (Fig. 3) carried by the rod 22 will then be separated from theabutment 39 at one end of the springhousing. This condition will existat the beginning of the downward stroke of the pump plunger, and as theplunger continues its downward movement,

the abutment 46 will engage and operate the pin 32 so as to release thelatch.3l, which then falls onto the rod 22. At this time the pumpplunger is located in a relatively low position, due to the excessdownward motion permitted by compression of the spring 40.

During the next upward strokeof the pump plunger, thenotches in the rod22 idly pass the released latch 3|, but during the following downwardstroke of the plunger, the latch 3| falls into a notch 38 so as to stopthe plunger at an intermediate stage of its downward movement. Thedriving members 31 and 38 continue in motion to relieve the compressionof the spring 40, which forces the abutment 39 onto the abutment 46.

Thereupon, the hook 21 (Fig. 3) continues in motionv independently ofthe stopped driving members 31 and 33, so as to release the uncou-.

bers 31 and 36 (Fig. 3), but these strokes are,

longer than the uniform strokes normally delivered to the driven members22 and 46. Immediately before each normal upward stroke of the plunger,the spring 40 is compressed, due to the weight of the column of liquidabove the plunger, and at this initial stage, the driving members 31and38 move independently of the driven membeginning of each normaldownward stroke, when the plunger is relieved of its load and permittedto fall in the trappe column of" liquid, at which'f the drivmembers3'l'and 38j to*mov e independently time the spring expands and permitsing of the driven'rnembers 22 and-4a.

However, when the spring is retained-under compression-during downwardstroke of the plunger, due to-the presence of'air or gas below theplunger, the relatively long stroke of the plunger is transmitted to thenotched'rod 22,50 as to engage the traveling stopping member (abutment46) with the normally stationary stopping member (pin 32). This actioneventually stops the plunger and disconnects it from the source ofpower. It will be observed that the stopping members are operated by thepump plunger which transmits its excess movement to the rod 22. This rodis driven by the source of power during each upward stroke of theplunger, but during each downward stroke, said rod is driven by theplunger.

Fig. 6 and Fig. 7 illustrate a simple form of the invention wherein thepolish rod 2| at the upper end of the string of sucker rods is driventhrough the medium of a beam 48 pivotally supported at 49 and connectedby means of a pitman 50 to a crank 5| actuated by a motor 52. This motormay be regarded as an internal combustion motor, or an electric motor,controlled by an electric circuit including wires 53 and a switch 54,said switch having an operating arm 55 movable to stop the motor. Anarcuate member 56, extending from the beam 48, is connected by means ofcables 51 to an outer housing 58. A bolt 59, extending from saidhousing, is provided with an adjusting nut 60 seated on said housing,and a head 6| at its lower end to receive a spring seat 62. A springhousing 63 surrounds the bolt 59, and a spring 64 is interposed betweentlieseat 62 and an abutment 65 at the upper end of said springhousing.The nut 60 canbe adjusted to'vary the initial compression of the spring64.

housing. A traveling stopping member 61 is adjustably clamped onto thepolish rod'2| so as to engage the normally stationary operating arm 55in response to excessive downward movement of the polish rod.

In the form shown by Fig. 6 and Fig. 7, the driving members include theouter housing 58 and the bolt 59. Uniform. strokes are imparted to thesedriving members in response to the rotary movement of the crank 5|,regardless of conditions in the well.

The companion driven members include the spring housing 63, the polishrod 2| and the traveling stopping member 61 carried by said polish rod.These driven members are pulled upwardly by the source of power, butthey movev downwardly in response to downward movements of the pumpplunger and sucker rods.

At the beginning of each upward stroke of the driving members, thespring 64 is compressed due to theweight of the tall column of liquidsupported on the pump plunger, and this compression is maintainedthroughout the upward stroke. However at the beginning of each normaldownward stroke the compression is relieved, as the load is then reducedto the weight of the pimip plunger and sucker rods, minus the buoyantefiect of the trapped column of liquid.

As a consequence, under normal operating con- '59. "An abnbrmalboiidmonexistsj' wh'eii ali e The polish rod 2| is connected to a cap 66 carriedby the lower end of the spring ditions, the strokes of the driyenmembers 65,

in shorter than the -members" '58 and uniform strokes of'the dri gas isdrawn into the tttpin ;,br workmg barrel, so as to' replace th *liquidbe ra'ssh's pr vious y and carry with it the polish rod 2|" a mmp: pingmember 61, was to move said stopping member into engagement with the arm55 of the stopping switch 54, thereby discontinuing the transmission ofpower to the pump plunger.

In the form shown by. Fig. 6 and Fig. 7, the plunger may be stoppedwhile in an abnormally low position, but it is not disconnected from thesource of power so the pumping operation can be resumed after anydesired interval by merely restoring the switch arm 55. In the formshown by Figures 1 to 5, the stopping impulse is given during anexcessive downward stroke, but the transmission of power is continueduntil the driving members are conveniently located in intermediatepositions where they can be readily disconnected from and thereaftercoupled to the source of power.

In addition to the various important advantages gained by automaticallystopping a pump in response to the delivery of air or gas to the pumpingelements, the specific devices herein shown tend to relieve the shockswhich occur under ordinary pumping conditions. It will be observed thatthe usual conditions include rapid changes in the load at the beginningof each stroke, and that such changes tend to strain or ill) distort thepower lines. Such distortion and strains are relieved by the powertransmission spring 40 or 64,. which serves as a shock ab- Anotherpeculiar action of the spring j liquid, a cylinder in which the plungerrecipro I cates, said cylinder having an..inlet through which liquid isdelivered to th eplunger under normal pumping conditions, said inletProviding for the admission of gaseous fluid to thecyb inder and plungerwhen. the flow of liquid is .in-

terrupted, a source of power" to operate. the;

plunger, a driving memberactuated by saidsource of power, and a. drivenmember con-. nected to said pumpplunger, the improvement comprising astopping device including a stopping member carried bysaid drivenpinember to discontinue the transmission of powerto. the '1 plunger when agaseousfiuid is deliveredto said plunger, said stopping device alsoincluding a yieldable shock absorber through/which the lift: ing poweris transmitted from said driving member to said driven member.

2. In an apparatus for lifting liquldlfrorn'a" f well provided with apump plunger movable upwardly to lift the liquid and movable downwardlyin the body of liquid, 9. cylinder in which the plunger reciprocates,said cylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, and a source of power to operate said plunger,the improvement which comprises a stopping device to discontinue thetransmission of power to the plunger when a gaseous fluid is transmittedto said plunger, said stopping device including a spring permittingexcess downward movement of the plunger in response to the presence ofgaseous fluid. below the plunger, and a'stopping member operated by saidplunger during said excess downward movement.

3. In an apparatus for lifting liquid from a well provided with a pumpplunger movable up-. wardly to lift the liquid and movable downward-.

ly in the body of liquid, a cylinder in which the plunger reciprocates,said cylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, and a source of power to operate said plunger,the improvement which comprises a stoppingdevice to discontinue thetransmission of power to the plunger when a gaseous fluid is transmittedto said plunger, said stopping device including a spring through whichthe lifting power is transmitted to said plunger, said spring permittingexcess downward movement of the plunger in response to the presence ofgaseous fluid below the plunger, a

traveling stopping member operated by said plunger, and a normallystationary, stopping member driven by said traveling member during saidexcess downward movement of the plunger.

4. In an apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid, a cylinder in which theplunger reciprocates, said cylinder having an inlet through which liquidis delivered to the plunger under normal pumping conditions, said inletproviding for the admission of gaseous fluid tothe cylinder and plungerwhen the flow of liquid is interrupted, and a source of power to liftthe plunger, said plunger" being free to move downwardly in the liquid,the improvement comprising a stopping device to discontinue thetransmission of power to the plupger when a gaseous fluid is deliveredto said plunger, said stopping device including a spring through whichthe lifting power is transmitted from said source of power to saidplunger, so as to permit excess downward movement of the plunger on saidgaseous fluid, and a stopping'member movable by said plunger to actuatesaid stopping device in response to excess downward movement of theplunger. 1

5. In an apparatus for lifting liquid from a well provided with a pumpplunger to lift the liquid, a cylinder in which the plungerreciprocates, said cylinder having an inletv throughwhich liquid isdelivered to the plunger under normal pumping conditions, said inletproviding for the'adm'ission of gaseous fluid to the cylinder andplunger when the flow of liquid is interrupted, a source of power tooperate the plunger, a driving member actuatedfby said source of power,and a driven member connected to said pump plunger, the improvementcomprising astopping device to discontinue the transmission of power tothe plunger when a gaseous fluid is, delivered to said plunger, saidstopping device including a power transmission spring through which .thelifting power is transmitted from said driving member to said drivenmember, and a stopping member carried by said driven member to actuatesaid stopping device.

6. In an apparatus for lifting liquid from a well provided with a pumpplunger to lift the liquid, a cylinder in which the plungerreciprocates, said cylinder having an inlet through which liquid isdelivered to the plunger under normal pumping conditions, said inletproviding for the admission of g'aseous fluid to the cylinder andplunger when the flow of liquid is interrupted, and a source of power tooperate the plunger, the improvement comprising a stopping device todiscontinue the transmission of power to the plunger when a gaseousfluid is delivered to said plunger, said stopping device including aspring through which the lifting power is transmitted from said sourceof power to said plunger, the strokes of said source of power beinguniform and longer than the normal strokes of said plunger, said springbeing yieldable in response to the lifting strokes of said source ofpower and plunger and relatively free during the normal return strokes,so as to avoid excess movement of the plunger during said normal returnstrokes, and a stopping member driven by said plunger to actuate thestopping device in response to excess movement of said plunger.

'7. In an apparatus for lifting liquid from a well provided with a pumpplunger to lift the liquid, a cylinder in which the plungerreciprocates, said cylinder having an inlet through which liquid isdelivered to the plunger under normal pumping conditions, said inletproviding for the admission of gaseous fluid to the cylinder and plungerwhen the flow of liquid is interrupted, a source of power to operate theplunger, a driving member actuated by said source of power, and a drivenmember connected to said pump plunger, the improvement comprising astopping device to discontinue the trans-. mission of power to theplunger when a gaseous fluid is delivered to said plunger, said stoppingdevice including a spring through which the lifting power is transmittedfrom said driving member to said driven member, the strokes of saiddriving member being uniform and longer than the normal strokes of saiddriven member, said spring being yieldable in response to the liftingstrokes of said driving member and plunger and relatively free duringthe normal return strokes, so as to avoid excess movement of the plungerand driven member during said normal return strokes, and a stoppingmember carried by said driven member to actuate the stopping device inresponse to movements of said driven member.

8. In an apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid, a source of power to liftthe plunger, 2. cylinder in which the plunger reciprocates, saidcylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger .when the flow ofliquid is interrupted, a driving member actuated by said source ofpower, and a driven member connected to said pump plunger, theimprovement comprising a stopping device to discontinue the transmissionof,power to the plunger when a gaseous fluid is delivered to saidplunger, said stopping device including a spring through which thelifting power is transmitted from said driving member to said drivenmember so as to permit excess downward movement of said plunger on saidgaseous fluid, the strokes of said driving member being uniform andlonger than the normal strokes of said driven member, said spring beingyieldable in response to the lifting strokes of said driving member andplunger and relatively free during the normal return strokes, so as toavoid excess downward movement of the plunger during said normal returnstrokes, and a stopping member carried by saiddriven member to actuatethe stopping device in response to excess downward movement of saidplunger.

9. In an apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid and movable downwardly inthe body of liquid, a cylinder in which the plunger reciprocates, saidcylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, a source of power to operate the plunger, adriving member actuated by said source of power, and a driven memberconnected to said pump plunger, the improvement comprising a stoppingdevice to discontinue the transmission of power to the plunger when agaseous fluid is delivered to said plunger, said stopping deviceincluding a power-transmission spring through which the lifting power istransmitted from said driving member to said driven member, saidtransmission spring being yieldable to permit an excess downward strokeof the plunger in response to the presence of gaseous fluid below theplunger and also yieldable in response to the lifting strokes of saiddriving member and plunger but relatively free during the normaldownward strokes, so as to avoid excess movement of the plunger duringsaid normal downward strokes,

and a stopping member carried by said driven member to actuate saidstopping device in response to excess downward movement of the plunger.

10. In an apparatus for lifting liquid from a well provided with a pumpplunger to lift the liquid, a cylinder in which the plungerreciprocates, said cylinder having an inlet through which liquid isdelivered to the plunger under normal pumping conditions, said inletproviding for the admission of gaseous fluid to the cylinder and plungerwhen the flow of liquid is interrupted, a source of power to operate theplunger, a driving member actuated by said source of power, and a drivenmember connected to said pump plunger, the improvement comprising astopping device to discontinue the transmission of power to the plungerwhen a gaseous fluid is delivered to said plunger, said stopping deviceincluding a compression spring through which the lifting power istransmitted from said driving member to said driven member, the strokesof said driv-' ing member being uniform and longer than the normalstrokes of said driven. member, said compression spring being yieldablein response to the lifting strokes of said driving member and plungerand relatively free to expand during the normal return strokes, so as toavoid excess movement of the plunger and driven member during saidnormal return strokes, and a stopping member carried by said drivenmember to actuate said.

stopping device in response to compression of said spring during thereturn strokes of the plunger. a

11. In an apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid and movable downwardly inthe body of liquid, a cylinder in which the plunger reciprocates, saidcylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said'inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, and a source of power to operate said plunger,the improvement which comprises an electric switch to discontinue thetransmission of power to the plunger when a gaseous fluid is transmittedto said plunger, a spring permitting excess downward movement of theplunger in response to the presence of gaseous fluid below the plunger,and a traveling stopping member operated by said plunger, said electricswitch having an operating member engaged by said traveling stoppingmember during said excess downward movement of the plunger.

12. In an apparatus for lifting liquid from a well provided with a pumpplunger to lift the liquid, a cylinder in which the plungerreciprocates, said cylinder having an inlet through which liquid isdelivered to the plunger under normal pumping conditions, said inletproviding for the admission of gaseous fluid to the cylinder and plungerwhen the flow of liquid is interrupted, a source'of power to operate theplunger, a driving member actuated by said source of power, and adrivenmember connected to said pump plunger, the improvement comprisinga stopping device including an electric switch to discontinue thetransmission of power to the plunger when a gaseous fluid is deliveredto said plunger, said stopping device also including a spring throughwhich the lifting power is transmitted from said driving member to saiddriven member, the strokes of said driving member being uniform andlonger than the normal strokes of said driven member, said spring beingyieldable in response to the lifting strokes of said driving member andplunger and relatively free during the normal return strokes, so as toavoid, excess movement of the plunger and driven member during saidnormal return strokes, and a stopping member carried by said drivenmember to actuate said electric switch in response to excess movement ofsaid driven member.

13. In an apparatus for lifting liquid from a well provided with apumpplunger movable upwardly to lift the liquid and movable downwardly inthe body of liquid, a cylinder in which the plunger reciprocates, saidcylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, a source of power to operate the plunger, adriving member actuated by said source of power, and a driven memberconnected to said pump plunger, the improvement comprising a stoppingdevice including an electric switch to discontimie the transmission ofpower to the plunger when a gaseous fluid is delivered to said plunger,said stopping device also including a power-transmission spring throughwhich the lifting power is transmitted from said driving member to saiddriven member, said transmission spring being yieldable to permit anexcess downward stroke of the plunger in response to the presence ofgaseous fluid below. the plunger excess downward movementof the plunger.

14. In an. apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid and movable downwardly inthe body of liquid, a cylinder in which the plunger reciprocates, saidcylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, and a source of power to operate said plunger,the improvement which comprises a stopping device to discontinue thetransmission of power to the plunger when a gaseous fluid is transmittedto said plunger, said stopping device including a spring permitting anexcess downward stroke of the plunger in response to the presenceofgaseous fluid below the plunger, a stopping member released by saidplunger during said excess downward stroke, said stopping member beingadapted to stop said plunger at an intermediate stage of the nextdownward stroke, and an uncouplingmember to disconnect the stoppedplunger from the source of power.

15. In an apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid and movable downwardly inthe body of liquid, 9. cylinder in which the plunger reciprocates, saidcylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of' gaseous fluid to the cylinder-and plunger when the flow ofliquid is interrupted, a source of power to operate said plunger, adriving member actuated by said source of power, and a driven member connected to said driving member, the improvement which comprises astopping device to discontinue the transmission of power to the plungerwhen r a gaseous fluid is transmitted to said plunger,

said stopping device including a spring between said driving member anddriven member permitting an excess downward stroke of the plunger inresponse to the presence of gaseous fluid below the plunger, a stoppingmember released by said driven member during said excess down wardstroke, said stopping member being adapted to stop said driven memberand plunger at an intermediate stage of the. next downward stroke, andan uncoupling device to disconnect the stopped plunger. from the sourceof power, said' uncoupling device being located between said spring andthe source of power and operable in response to a reduction in thepressure of said spring.-

- .16. In an apparatus for lifting liquid from a well provided with apump plunger movable upwardly to lift the liquid and movable downwardlyin the body of .liquid, a cylinder in which the plunger reciprocates,said cylinder having an inlet through which liquid is delivered to theplunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, a source of power to operate the plunger, adriving member actuated by said source of power, and a driven memberconnected to said pump plunger, the improvement comprising a stoppingdevice to discontinue the transmission of power to the plunger when agaseous fluid is delivered to said plunger,

said stopping device including a power-transmission spring through whichthe lifting ,power is transmitted from said driving member to saiddriven member, said transmission spring being yieldable to permit anexcess downward stroke of the plunger in response to the presence ofgaseous fluidbelow the plunger and also yieldable in response to thelifting strokes of said driving member and plunger but relatively freeduring the normal downward strokes, so as to avoid excess movement 'ofthe plunger during said normal downward strokes, a stopping mem-'' bercarried by said driven member to stop said driven member in response toexcess downward movement of the plunger, said driving member beingmovable independently of the stopped driven member in response to thepressure of said power-transmission spring, and an uncoupling memberreleased in response to the last mentioned movement of said drivingmember so as to release the driving member from the source of power.

17. In an apparatus for lifting liquid from a well provided with a pumpplunger movable upwardly to lift the liquid and movable downwardly inthe body of liquid, a cylinder in which the plunger .reciprocates, saidcylinder having 'an inlet through which liquid is delivered to the'plunger under normal pumping conditions, said inlet providing for theadmission of gaseous fluid to the cylinder and plunger when the flow ofliquid is interrupted, a source of power to operate the plunger, adriving member actuated by said source of power, and a driven memberconnected to said pump plunger, the improvement comprising a stoppingdevice to discontinue the transmission of power to the plunger when agaseous fluid is delivered to said plunger, said stopping deviceincluding a power-transmission spring through which the lifting power istransmitted from said driving member to said driven member, saidtransmission spring being yieldable to permit an excess downward strokeof the plunger in response to the presence of gaseous fluid below theplunger and also yieldable in response to the lifting strokes of saiddriving member and plunger but relatively free during the normaldownward strokes, so as to avoid excess movement of the plunger duringsaid normal downward strokes, a stopping member released by said drivenmember in response to excess downward movement of the plunger, saidstopping member being adapted to stop said driven source of power, saiduncoupling device being located between said spring and the source ofpower and free to release said driving member when the pressure of saidspring is reduced.

18. In an apparatus for lifting liquid from a well provided with a pumpplunger to lift the liquid, a cylinder in which the plungerreciprocates, said cylinder having an inlet through which liquid isdelivered to the plunger under normal pumping conditions, said inletproviding for the admission of gaseous fluid to the cylinder and plungerwhen the flow of liquid -is interrupted,

a source of power to operate the plungeW driving member actuated by saidsource of po r, 7

and; a driven member connected to said pump plungenthe improvementcomprising a stopping device to discontinue the transmission of power tothe plunger when a gaseous fluid is delivered 5 to said plunger, saidstopping device including a compression spri g through which the liftingpower is transmi ted from said driving member to said dr'iven member,the strokes of said driving member being uniformand longer thanthe norl0mal strokes of said driven membeu'said compression spring beingyieldable in response to the lifting strokes of said driving member andplunger and relatively free to expand during the normal return strokes,so as to avoid excess movement of the plunger and driven member duringsaid normal return strokes, a coupling device located between saidspringandthe source of powenand' connecting said drivingmember to the sourceof power, said coupling device in-' CERTIFICATE OF CORRECTION;

Paten1 N o. 2,202,5 0l|.. May '2 191p.

JOHN G. 1 It ishereby eertified that error appears 1:; bhe abovepumbered patent, requiring borrection as fellofisz' In the grant'-,.1ine15 -f or""an:1 end J. N. Seott" read -and J. w, Scottand ,tnai: the saidLeti zers Patenfi should be reed wlfih' this correction therein that,the Same may conform to th e rec 0rd of the ease in flieraten't Office.I

Signed. me. s'eaied this 9th=day of ul A'Q'D. 191m.

. enry: Van Ais' dal'e', (Se'alj Acfiing commisei'oner of Patents.

